Following a surge in Apple stock performance, Apple CEO Tim Cook last week collected the maximum number of restricted stock units -- totaling 560,000 shares -- afforded by his incentive plan, raking in $89.2 million for the effort.

Cook's award of 560,000 vested RSUs, and the subsequent sale of $43.2 million common shares, was disclosed in a Securities and Exchange Commission filing on Monday.

The chief executive on Aug. 24 saw 280,000 units of time-based RSUs and another 280,000 units of performance-based RSUs vest in accordance with an incentive plan adopted by Apple's board. In order for Cook to collect the bonus in full, Apple's shareholder return for the past three years had to beat two-thirds of the companies in the S&P 500.

Adjusted for dividends, Apple's average starting value was calculated at $97.74 on Aug. 25, 2014, while the average ending value was calculated at $166.72 on Aug. 27, 2017. Apple's total shareholder return for the three-year period was 70.57 percent, good enough to rank in 80th place of the 420 companies included in the comparison.

If Apple's performance fell in the middle third of the S&P 500, Cook's RSU award would have been reduced by half. Cook would have collected nothing if Apple stock finished in the bottom-third.

Last Thursday, Apple disposed of 291,377 shares to satisfy the minimum statutory tax withholding requirements on vesting of RSUs. Cook on Friday and today sold the remaining vested RSUs in a series of transactions ranging from $159.96 to $161.43 pursuant to his trading plan. The executive netted some $43.2 million as a result of the selloff.

Cook retains 901,474 shares of common stock in his trust worth $145.6 million at the end of trading today. Another 2,940,000 RSUs are pending, including a batch of 700,000 RSUs scheduled to vest on Aug. 24, 2021. The most recent 280,000-unit award was the second of six performance-based RSU packages set to vest in annual installments through 2021.